Control arrangement for fuel injection devices



Jan. 2, 1962 R. J. WIRSCHING ETAL 3,015,326

CONTROL ARRANGEMENT FOR FUEL INJECTION DEVICES Filed March 30, 1959 PUMPP/sm/v TEMPE RH TUBE ZESPONS/VE TEMPE/PH TUBE EESPONS/VE'll/III/IIII/I/l/IIIII/IA IIIIIIIIIIIIIIIIIII C001. 1N6 WA 7' EHINVENTORS ROBERT J. WIRSCHING ULRICH CONRAD w @1 1 wza wm ATTOR YS R071?7'! UNA SP'EP EESPONSIVE l THR a T TL E United States Patent 3,015,326CQNTRQL ARRANGEMENT FOR FUEL INJECTION DEVICES Robert I. Wh'sching,Korntal, near Stuttgart,

Conrad, Ludwigsburg-Ossweil, Germany, Daimler-Benz Alrtiengeselischaft,heim, Germany Filed Mar. 36, 1959, Ser. No. 802,912 Claims priority,application Germany Apr. 12, 1958 15 Claims. (Cl. 123-440) The presentinvention relates to a control arrangement for the fuel injectionquantity of fuel injection pumps, especially of mixture-compressinginternal combustion engines of the injection-type, which adjustsautomatically the injection quantity of the fuel, in addition to anautomatic adjustment in dependence on the rotational speed and on thethrottle valve position, also in dependance on the air pressure, on theair temperature, and on the cooling-water temperature.

The present invention is concerned with the problem to improve such acontrol arrangement and to complete the same so as to perform itsintended function in a more reliable and appropriate manner.Additionally, the present invention seeks to provide a continuouscorrection over the entire control range in dependence on the prevailingair density.

The present invention is characterized essentially by a double-armedpivotal lever operative to transmit the control magnitudes, the pivotpoint or axis of rotation of which is automatically adjusted by acooling-water temperature sensing device and by one or severalbarometric pressure boxes as well as by an air-temperature sensingdevice whereby the transmission ratio of the two arms of thedouble-armed lever changes in dependence on the prevailing air density.

According to the adjusting and control principle of the presentinvention, it is possible to undertake an accurate metering of theinjected fuel quantity in dependence on the rotational speed, on thethrottle valve position as well as on the cooling-water temperature, theair temperature and the barometric condition. Furthermore, it isachieved in connection with an arrangement in accordance with thepresent invention that the forces within the lever mechanism of thecontrol arrangement are effective only in one direction, i.e., areeffective only unilaterally. The individual members thereby all abutunilaterally at the places of connections thereof so that no play canoccur which would impair the accuracy of the operation of the controlarrangement in accordance with the present invention. Furthermore, theaccessibility for the assembly and the fine adjustment of the controlarrangement is considerably improved by the present invention.

in a particularly appropriate arrangement of the present invention, thedouble-armed lever may cooperate with a three-dimensional cam member ofknown suitable construction which is adapted to be both axiallydisplaced and rotated under the influence of the throttle valve positionand the rotational speed respectively. It is significant thereby for thepresent invention that one of the lever arms of the double-armed leverwhich is constructed as sensing lever is adjusted by thethree-dimensional cam member, and that the other end of the double-armedlever adjusts or displaces the control rack of the injection pump andthat the pivot point or axis of rotation of the doublearmed lever isadjustable approximately perpendicularly to the longitudinal directionof the lever under the influence of a cooling-water sensing device andthat simultaneously therewith the pivot axis of the double-armed leveris adjustable in the longitudinal direction thereof to therebyeffectively vary the transmission ration of the lever, under theinfluence of the air temperature sensing and Ulrich assignors totuttgart-Unterturk- 7 3,015,326 Patented Jan. 2, 1962 device and of thebarometric pressure boxes, i.e., under the influence of the air density.

A further advantage is achieved in connection with the controlarrangement according to the present invention by enabling apercentagewise correction in dependence on the air density over theentire control range thereof with an engine operating under normal hotrunning conditions, i.e., at normal operating temperatures. With asetting of zero-fuel supply and an engine at normal operatingtemperature, the control magnitude derived from the air density is nolonger fuel pump.

The percentage correction is achieved by means of elongated or oblongapertures in the sensing lever and in the flattened end of the slidemember which, with a setting of zero-fuel supply and the positionthereof corresponding to the temperature of the normally operatingengine are disposed coincidental one above the other so that both ofthese apertures coincide. The coinciding elongated apertures then formthe ineffectual guidance for a connecting shackle or lug which transmitsto the doublearmed sensing lever the control magnitudes of the airdensity in the other positions.

Accordingly, is is an object of the present invention to provide acontrol arrangement for injection-type mixturecompressing internalcombustion engines in which the control of the fuel injection quantityis automatically controlled in dependence, not only on the rotationalspeed of the engine and on the position of the throttle valve, but alsoin dependence on the air pressure, on the air temperature and thecooling-water temperature.

Still another object of the present invention is the provision of acontrol arrangement automatically adjusting the amount of injected fuelin an automatic manner in dependence on the engine speed, the throttlevalve position, the air density and the cooling water temperature of theengine.

Still a further object of the present invention is to provide a controlarrangement of the type described hereinabove for automaticallyadjusting the amount of injected fuel in a continuous manner over theentire control range in dependence on the prevailing atmosphericconditions, especially the density thereof.

Still another object of the present invention resides in the provisionof a control arrangement automatically adjusting the quantity ofinjected fuel in dependence on the rotational speed, the throttle valveposition, the air temperature, the air pressure and the cooling-watertemperature, in which any play in the control arrangement is essentiallyeliminated thereby improving the operation condition and the accuracy ofoperation thereof.

A further object of the present invention resides in the provision of acontrol arrangement for automatically controlling the amount of injectedfuel in injection-type mixture-compressing internal combustion engineswhich facilitates assembly, repair and fine adjustment of the contIOiarrangement.

These and other objects, features and advantages of the presentinvention will become more obvious from the following description, whentaken in connection with the accompanying drawing, which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

FIGURE 1 is a schematic view, partly in cross section, of portions ofthe control arrangement in accordance with the present invention, and

FIGURE 2 is a part perspective, part sectional view on an enlargedscale, of the central part of the lever mechanism for transmitting andcoordinating the individual control magnitudes, and of elements of thecontrol arrangement not illustrated in FIGURE 1.

Referring now to the drawing wherein like reference transmitted to thecontrol rack of the this type of sensing ing device 1, which isconnected to any conventional temperature responsive device in thecooling water cir-- cuit, the air temperature sensing device 2, which isconnected to a temperature responsive device in the air intake, andthree barometric pressure boxes 3 belong to devices which areillustrated in FIG URE 1. Additional control magnitudes are transmittedby the three-dimensional cam member 4 to the lever mechanism asillustrated in FIGURE 2 as will be discussed hereinafter.

The lever mechanism itself which serves for purposes of transmitting theindividual control magnitudes and coordinating the magnitudes into asingle adjusting magnitude for the control rack of the injection pumpconsists of a pivot lever 5 which is pivotally supported essentially inthe center thereof on an eccentric bolt member 6. A further lever 7 issecured at the bolt member 6 which itself is actuated by theair-temperature sensing device 2. The pivot lever 5 is operativelyconnected over a servo device or amplifier 8 of suitable constructionwith an angle lever or bell crank 9. The connecting shackle or lug 10 isoperatively connected with the bell crank 9 at one end thereof andcarries at the other end thereof the bolt member 11 which is disposedwithin the two elongated apertures 12 and the elongated aperture 13(FIGURE 2) of the fork-shaped double-armed sensing lever 14 and of theflattened end 15 of the slide member or plunger 16 respectively. Theslide or plunger member 16 is operatively connected over a pivot lever17 with the cooling-water-temperature sensing device 1. For purposes ofclarity of FIGURE 1, the two elongated apertures 12 and the elongatedaperture 13 in the doublearmed sensing lever 14 and the flattened end 15of the slide member 16 are shown only in FIGURE 2. The double-armedsensing lever 14 includes at one end thereof the sensing roller orfollower 18 which is in continuous engagement with the three-dimensionalcam member 4 and is thereby adjusted during any rotary or axial movementof the latter. A drag-lever 19 is pivotally secured to this same end ofthe sensing lever 14 which drag-lever 19 is pivotally connected at theother end thereof with the control housing and is operative to securethe sensing device 14 against longitudinal displacement. At the otherend of the sensing lever 14, i.e., at the end thereof opposite thesensing roller 18, the lever 14 acts on the control rack 20, of theinjection pump (not shown) with the resulting adjusting controlmagnitude.

Operation The control arrangement in accordance with the presentinvention operates as follows: As shown in FIG- URE 2, thethree-dimensional member 4 is axially displaced in the direction ofdouble arrow 21 in dependence on the throttle valve position and isrotated in the direction of double arrow 22 under the influence of therotational speed. Both. of these movements, namely the axially androtary displacement of the cam member 4 may be achieved in any suitable,conventional manner known in the prior art. For example, the rotationalspeed control means may include crankshaft speed responsive means, andsuitable means to rotate the three dimensional cam member 4. The meansfor axially displacing the cam member 4 may include cable meansconnected at one end to the member 4 and at the other end to lever meansresponsive to the positions of the throttle valve. By the movements ofthe three-dimensional cam member 4 under the influence of the throttlevalve position and the rotational speed, the sensing roller 18 isadjusted in the direction of the double arrow 23 (FIGURES l and 2). Themovements of the roller member 13 are transmitted over the sensing lever14 to the control rack 20 against or in the direction of the force of aspring corresponding to the direction of the double arrow 24 anddepending on the direction of the actual adjustment. The cooling-Watertemperature sensing device 1 adjusts simultaneously the pivot lever 17by reason of the change in the length thereof, i.e., in the longitudinaldirection thereof. The cooling-water temperature sensing device 1 maythereby be of any conventional construction which translates changes inthe temperature of the cooling water into longitudinal movements of amechanical member. The slide member or plunger 16 is thereupon actuatedby the pivot lever 17 and transmits the mov ments corresponding tovariations in the cooling water temperature to the sensing lever 14. Theparticular manner of transmission thereof will be described more fullyhereinafter with reference to FIGURE 2.

The control magnitudes of the air temperature sensing device 2 and ofthe barometric pressures boxes 3 translated into longitudinal changes ordisplacement by the sensing devices 2 and 3 are each transmitted to thedoublearmed pivot lever 5, and more particularly in such a manner thatthe two-armed pivot lever 5 is pivoted at one arm thereof over anadjusting screw 25 by the barometric pressure boxes 3 and that theeccentric bolt member 6 which serves as bearing support for the pivotlever 5 is rotated over lever 7 by the air-temperature sensing device 2in the direction of the double arrow 26. The resulting adjustingmagnitude of the two-armed pivot lever 5 is transmitted to the servodevice 8, whereby the servo device or amplifier 8 serves the purpose toamplify the control magnitude applied thereto by the pivot lever 5 andto transmit the thus amplified control magnitude to the angle lever 9.On the other hand, prevent that any reverse or retrograde adjustingforces which act on the servo device 8 in the direction from angle lever9 are transmitted on to the pivot lever 5. The special construction ofthe servo device 8 and the arrangement of the eccentric shaft 6 and ofthe lever 7 make possible to achieve that the barometric pressure boxes3 are loaded or acted on by a far-reachingly constant and relativelyslight force which benefits to a large extent the measuring accuracythereof. The small spring 27 of the servo device 8 abuts at the left endthereof, as seen in FIGURE 1, against stop member 28 which is rigidlyconnected with the sleeve 29. The other end of the spring 27 issupported over the control piston 30 and pivot lever 5 against thebarometric pressure boxes 3. By reason of this particular constructionof the servo device 8, it is possible to realize a spring force orspring tension exerted on the barometric pressure boxes 3 which remainsessentia ly constant throughout. The angle lever or bell-crank 9 effectsan adjustment of the connecting lug or shackle 10. The connecting lug orshackle 10 is provided at the end thereof remote from the angle lever 9with a bolt member 11 which extends through both elongated apertures 12and through the elongated aperture 13 (FIG- URE 2) in sensing lever 14and in the flattened end 15 of plunger or slide member 16.

By reason of the fact that the sensing lever 14 is constructed in afork-like manner, as shown particularly in FIGURE 2, and by reason ofthe fact that two arms of the fork thereof form two essentially fiatparts disposed fective in that connection as connecting bolt, and byreason of the fact that the connecting lug or shackle is alsoconstructed in a fork-like manner the arms of which extend up to theregion of the sliding head portion and of the center of the sensinglever 14 and are connected thereat with each other, as alreadymentioned, by means of the bolt member 11, the present inventionachieves a control system in which the control magnitudes of the airdensity which are derived from the air temperature sensing device 2 andthe barometric pressure boxes 3, and which are transmitted by theconnecting lug or shackle 10, lead to a variation of the transmissionratio of the two arms of the double-armed sensing lever 14. The boltmember 11 thereby moves within the elongated apertures 12 and 13. Sincethe bolt member 11 simultaneously therewith also represents the pivotpoint or axis of rotation of the double-armed lever 14, the two arms ofthe sensing lever 14 are respectively shortened or lengthened wherebythe aforementioned change in the transmission ratio of lever 14 isachieved. Simultaneously therewith, the bolt member 11, and therewithalso the sensing lever 14, is adjusted by the movement of the slidingmember or plunger 16.

The movements of the sliding member or plunger 16 are directedessentially perpendicularly to the longitudinal direction of thedoublearmed lever 14 which has as a result the fact that thetransmission ratio of the doublearmed lever 14 is essentially unafiectedby the movements of the siding or plunger member 16, i.e., by thecontrol magnitude of the cooling-water sensing device 1. Thetransmission ratio is essentially adjusted only by the movements of theconnecting lug or shackle 1t), i.e., of the bolt member 11, in thelongitudinal direction of the double-armed connecting lever 14. Thetransmission ratio is, therefore, primarily dependent on the prevailingair density. As a result thereof, a correction over the entire controlrange in dependence on the prevailing air density is provided by thecontrol arrangement in accordance with the present invention.

The elongated apertures 12 and 13 in the plate-shaped sliding headmember 15 and in the sensing lever 14 respectively are so arranged andconstructed that with a zero-fuel supply adjustment and with normaloperating temperatures of the engine they come to lie above one anotherin a substantially co-incidental manner. This position is shown inFIGURE 2. In this position, the bolt member 11 moves Within theapertures 12 and 13 without causing any displacement or adjustment ofthe sensing lever 14.

While we have shown and described one embodiment in accordance with thepresent invention, it is understood that the same is not limited theretobut is susceptible of many changes and modifications within the spiritand scope of the present invention and we, therefore, do not wish to belimited to the specific details described and shown herein but intend tocover all such changes and modifications as are encompassed by the scopeof the appended claims.

We claim:

1. A control arrangement for controlling the fuel injection quantity,particularly of mixture-compressing injection-type internal combustionengines comprising first means for adjusting the quantity of injectedfuel, second means for producing a control magnitude in response to therotational speed of the engine, third means for producing a controlmagnitude in dependence on the engine control throttle position, fourthmeans for producing a control magnitude in dependence on the airpressure, fifth means for producing a control magnitude in dependence onthe air temperature, sixth means for producing a control magnitude independence on the cooling-water temperature, and seventh means fortransmitting the control magnitudes from said second, third, fourth,fifth and sixth means to said first means to provide a continuouscorrection over the entire control range in dependence on the prevailingair density including a double armed pivot lever means transmitting thecontrol magnitudes and having a movable pivot means, and means fordisplacing said pivot means by any one of said sixth means, fifth meansand fourth means, the transmission ratio of the two arms of saiddouble-armed lever means being adjustable in dependence on theprevailing air density.

2. A control arrangement according to claim 1, wherein said first meansis constituted by the adjusting rack of the injection pump, saiddouble-armed lever means constituting a sensing lever, three-dimensionalcam means con trolled by said second and third means and operativelyconnected with one arm of said double-armed lever means, and the otherarm of said double-armed lever means being operatively connected withsaid adjusting rack to selectively adjust the latter.

3. A control arrangement according to claim 1, wherein said pivot meansis so arranged as to be displaceable by said sixth means in a directionessentially perpendicularly to the longitudinal direction of saiddouble-armed lever means, and wherein said pivot means is operative tobe adjusted essentially in said longitudinal direction by said fourthand fifth means to thereby vary the lever ratio of said double-armedlever means.

4. A control arrangement according to claim 3, wherein said sixth meansincludes a sliding member provided with an elongated aperture in thefree end thereof, said doublearmed lever means also being provided withaperture means so arranged as to coincide with said aperture in therespective positions thereof corresponding to a setting of zero-fuelsupply and under normal engine operating temperature conditions tothereby render ineffectual the control magnitudes on said double-armedlever from said fourth and fifth means.

5. A control arrangement according to claim 4, further comprisingconnecting means pivotally secured at one end t ereof to saiddouble-armed lever means and said sliding member by said pivot meansengaging said aperture and said aperture means and operatively connectedto said fourth and fifth means at the other end thereof.

6. A control arrangement according to claim 1, further comprisingdrag-lever means pivotally secured at one end thereof with saiddouble-armed lever means and, at the other end thereof, with the controlhousing to prevent longitudinal displacement of said double-armed levermeans.

7. A control arrangement according to claim 6, wherein said double-armedlever means constitutes the sensing lever and is constructed in afork-like manner including two arm portions of the fork formingflattened parts disposed one above the other at a predetermineddistance, a three-dimensional cam member operatively connected with saidsecond and third means to provide a spatial displacement upon axial androtational movements thereof corresponding to the control magnitudesderived from said second and third means, a cam-follower roller abuttingagainst said three-dimensional cam member and accommodated within saidtwo arms and pivotally secured therein, said sixth means including asliding member provided with a flattened end portion surrounded on bothsides thereof by said two arm portions of said fork-shaped, double-armedlever means within the central region thereof, said flattened endportion being provided with an elongated aperture cooperating with theapertures provided in said two arm portions of said double-armed,forkshaped lever means through said pivot means, said doublearmed levermeans being provided at the free end thereof with abutment means forengagement with the springloaded end of the control rack formed by saidfirst means constituting the injection pump.

8. A control arrangement according to clairn 7, wherein said drag levermeans is also fork-shaped and is pivotally secured with saiddouble-armed lever means at the pivotal connection thereof with said camfollower roller.

9. A control arrangement according to claim 8, further comprising afork-shaped connecting shackle operatively connected at one end thereofwith said fourth and fifth means, the arms of said fork-shapedconnecting shackle extending up to the region of said sliding member andthe center portion of said doube-armed lever means and being connectedthereat by said pivot means extending through said elongated apertures.

10. A control arrangement for controlling the fuel injection quantity,particularly of mixture-compressing injection-type internal combustionengines, comprising first means for adjusting the quantity of injectedfuel, second means for producing a control magnitude in response to therotational speed, third means for producing a control magnitude independence on the engine throttle position, fourth means for producing acontrol magnitude in dependence on the air pressure, fifth means forproducing a control magnitude in dependence on the air temperatu're,sixth means for producing a control magnitude in dependence on thecooling-water temperature, and seventh means for transmitting thecontrol magnitudes from said second, third, fourth, fifth and sixthmeans to said first means to provide a continuous correction over theentire control range in dependence on the prevailing air density, saidfourth means including barometric pressure box means and said fifthmeans including an air-temperature sensing means, a common pivot lever,means transmitting the control magnitudes from said barometric pressurebox means and said air-temperature sensing means to said common pivotlever, servo amplifier means having input means and output means, meansfor applying the control magnitudes from said common pivot lever to theinput means of said servo amplifier means, and means for applying theamplified control magnitudes from the output means of said servoamplifier means to said seventh means, said servo amplifier meansincluding means protecting said barometric pressure box means againstretrograde loads.

11. A control arrangement according to claim 10, wherein said last meansincludes a sleeve member in said servo amplifier means displaced bypressure, a spring within said sleeve member, an abutment in said sleeverigidly connected therewith, and a control piston member operativelyconnected with said barometric pressure box means, said spring abuttingat one end against said abutment and at the other end thereof againstsaid control piston memher.

12. A control arrangement for automatically controlling the injectedfuel quantity, especially of mixture-compressinginjection-type internalcombustion engines in which the injected fuel quantity is automaticallycontrolled, inaddition to a control in dependence on the rotationalspeed and the engine throttle valve position, also in dependence on theair pressure, the air temperature and the engine cooling medium andwhich produces a continuous correction over the entire control range independence on the prevailing air density comprising adjusting-meansforselectively varying the amount of injected fuel, double-armed pivotallever means transmitting the displacements corresponding to therespective control magnitudes to said fuel adjusting means includingadjustable pivot means, means for adjusting said pivot means in responseto said engine cooling medium, and sensing means responsive to the airdensity for varying the transmission ratio of the two arms of saiddouble-armed lever means in dependence on the prevailing air density.

13. A control arrangement according to claim 12, wherein said sensingmeans responsive to the air density for varying the transmission ratioof the two arms is inefiectual to change the position of said levermeans with the first means adjusted to zero-fuel supply and under normaloperating temperature conditions of said engine.

14. A control arrangement according to claim 13, wherein said sixthmeans is ineffectual to vary the transmission ratio of said double-armedlever means with said first means adjusted to zero-fuel position andwith said temperature operating under normal running conditions.

15. A control arrangement according to claim 12, wherein said sensingmeans includes servo amplifier means preventing retrograde loads fromsaid lever means to said air density sensing means to thereby protectthe latter against varying forces.

References Cited in the file of this patent UNITED STATES PATENTS

